www.rti.orgRTI International is a registered trademark and a trade name of Research Triangle Institute.
IMPROVE Steering Committee Meeting
Petaluma, California 2019
Tracy Dombek, Ions Report
RTI International
2
RTI International Minimum Detection Limits
3
Calibrate systems daily Quality Controls before and after every ten samples analyzed. Duplicates at a rate of 3 per batch of 50. Instrument and Method Blanks every batch extracted and analyzed. Random reanalysis of 5% of the sample total. Re-extraction of filters to evaluate extraction efficiencies.
Chloride Nitrite Nitrate Sulfate
2019 0.005 ppm 0.010 ppm 0.008 ppm 0.011 ppm
RTI International Quality Control Standards
4
Average Recovery Chloride
Average RecoveryNitrite
Average RecoveryNitrate
Average RecoverySulfate
QC-Lown= 587 101% 97.2% 98.7% 99.2%
QC-Medn=901 101% 98.8% 99.4% 99.7%
QC-Med-HIn=560 101% 100% 99.9% 99.8%
QC-Highn-= 297 101% 102% 100% 101%
Instrument Control Charts
170
180
190
200
210
220
230
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Low QC - Cl
350360370380390400410420430440450
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Low QC - NO2
1070
1120
1170
1220
1270
1320
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Low QC - SO4
520
540
560
580
600
620
640
660
680
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Low QC - NO3
RTI International Instrument Control Charts
6
425
445
465
485
505
525
545
565
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n (u
g/L)
Analysis Date
Instrument MED QC - Cl
850
900
950
1000
1050
1100
1150
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument MED QC - NO2
1325
1375
1425
1475
1525
1575
1625
1675
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n (u
g/L)
Analysis Date
Instrument Med QC - NO3
2675
2775
2875
2975
3075
3175
3275
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Med QC - SO4
RTI International Instrument Control Charts
7
890
940
990
1040
1090
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n (u
g/L)
Analysis Date
Instrument Med-HI QC - Cl
17501800185019001950200020502100215022002250
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Med-Hi QC – NO2
2690
2790
2890
2990
3090
3190
3290
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Med-Hi QC - NO3
5390
5590
5790
5990
6190
6390
6590
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
Instrument Med-Hi QC - SO4
RTI International 25th, 50th,& 75th Percentile Chloride
8
Approximate Air Concentrations
25th Chloride - 0.016 ug/m3
50th Chloride – 0.031 ug/m3
75th Chloride - 0.061 ug/m3
1517192123252729313335
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA25 25th Percentile Concentration Chloride
2530354045505560657075
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA50 50th Percentile Concentration Chloride
859095
100105110115120125130135
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA75 75th Percentile Concentration Chloride
RTI International 25th , 50th , & 75th Percentile Nitrite
9
7
9
11
13
15
17
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA25 25th Percentile Concentration Nitrite
1214161820222426283032
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA50 50th Percentile Concentration Nitrite
25
30
35
40
45
50
55
60
65
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA75 75th Percentile Concentration Nitrite
Approximate Air Concentration
25th Nitrite – 0.007 ug/m3
50th Nitrite – 0.013 ug/m3
75th Nitrite – 0.026 ug/m3
RTI International 25th, 50th , & 75th Percentile Nitrate
10
Approximate Air Concentration
25th Nitrate – 0.092 ug/m3
50th Nitrate – 0.18 ug/m3
75th Nitrate – 0.36 ug/m3
130
135
140
145
150
155
160
165
170
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA25 25th Percentile Concentration Nitrate
530
550
570
590
610
630
650
670
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA75 75th Percentile Concentration Nitrate
260
270
280
290
300
310
320
330
340
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA50 50th Percentile Concentration Nitrate
RTI International 25th, 50th, & 75th Percentile Sulfate
11
Approximate Air Concentration
25th Sulfate – 0.30 ug/m3
50th Sulfate – 0.60 ug/m3
75th Sulfate – 1.2 ug/m3
1775182518751925197520252075212521752225
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA75 75th Percentile Concentration Sulfate
425
445
465
485
505
525
545
565
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA25 25th Percentile Concentration Sulfate
425
445
465
485
505
525
545
565
12/16/18 2/4/19 3/26/19 5/15/19 7/4/19 8/23/19 10/12/19
Con
cent
ratio
n ug
/L
Analysis Date
QA50 50th Percentile Concentration Sulfate
RTI International Duplicate Precision
12
Chloride Percent DifferencesAverage = -0.28%Median = 0.03%
Maximum = 35.3%Minimum = -130.%
Count = 789Failures 0.3%
Nitrite Percent DifferencesAverage = 4.2%
Median = 0%Maximum = 200%
Minimum = -200 %Count = 789Failures 0%
y = 1.0006x + 0.3519R² = 0.9988
0500
10001500200025003000350040004500
0 1000 2000 3000 4000 5000Dup
licat
e Sa
mpl
e C
once
ntra
tion
(ug/
L)
Sample Concentration (ug/mL)
2019 Chloride Duplicate Precision
y = 1.0046x - 0.1333R² = 0.9856
-50
0
50
100
150
200
250
0 50 100 150 200 250
Dup
licat
e Sa
mpl
e C
once
ntra
tion
(ug/
L)
Sample Concentration (ug/mL)
2019 Nitrite Duplicate Precision
RTI International Duplicate Precision
13
Nitrate Percent DifferencesAverage = 0.10%Median = 0.07%Maximum = 38%
Minimum = -38 %Count = 789Failures 0%
Sulfate Percent DifferencesAverage = 0.19%Median = 0.06%Maximum = 200%Minimum = -146%
Count = 789Failures 0%
y = 0.9995x + 0.0247R² = 1
0
5000
10000
15000
20000
25000
0 5000 10000 15000 20000 25000
Dup
licat
e Sa
mpl
e C
once
ntra
tion
(ug/
L)
Sample Concentration (ug/mL)
2019 Nitrate Duplicate Precision
y = 0.9987x + 0.7877R² = 0.9999
0
5000
10000
15000
20000
25000
0 5000 10000 15000 20000 25000
Dup
licat
e Sa
mpl
e C
once
ntra
tion
(ug/
L)
Sample Concentration (ug/mL)
2019 Sulfate Duplicate Precision
RTI International Blank Analyses
0
2
4
6
8
10
12
14
16
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Chl
orid
e C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Chloride Instrument Blanks
0
5
10
15
20
25
30
35
40
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Chl
orid
e C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Chloride Method Blanks
00.10.20.30.40.50.60.70.80.9
1
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Nitr
ite C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Nitrite Instrument Blanks
0
5
10
15
20
25
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Nitr
ite C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Nitrite Method Blanks
RTI International Blank Analyses
RTI International Blank Analyses
00.10.20.30.40.50.60.70.80.9
1
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Nitr
ate
Con
cent
ratio
n (u
g/L)
Analysis Date
2019 Nitrate Instrument Blanks
0
2
4
6
8
10
12
14
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Nitr
ate
Con
cent
ratio
n (u
g/L)
Analysis Date
2019 Nitrate Method Blanks
0
5
10
15
20
25
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Sulfa
te C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Sulfate Instrument Blanks
0
5
10
15
20
25
12/16/2018 2/4/2019 3/26/2019 5/15/2019 7/4/2019 8/23/2019 10/12/2019
Sulfa
te C
once
ntra
tion
(ug/
L)
Analysis Date
2019 Sulfate Method Blanks
RTI International Reanalysis
Chloride Nitrite Nitrate Sulfate
2019 median
RPD 0.03% 0% -0.59% 0.01%
2019 Average
RPD 0.26% -0.51% 0.21% 0.52%
RTI International Routine Filter Re-Extraction
Extraction efficiencies were evaluated on nearly 200 samples Efficiency is determined by dividing the result measured on the
re-extracted filter by the sum of the original and re-extracted results.
Chloride Nitrite Nitrate Sulfate
98.0% 95.5% 99.9%
RTI International Comparison of Nitrate Measured in Field Blanks
RTI International Quartile Concentrations
YearQ1
ug/mL
Q1 air concentration
ug/m3 Q2 ug/mL
Q2 air concentration
ug/m3Q3
ug/mL
Q3 air concentration
ug/m3
2009 0.039 0.024 0.045 0.028 0.050 0.0312010 0.048 0.029 0.058 0.035 0.072 0.0442011 0.023 0.014 0.028 0.017 0.038 0.0232012 0.023 0.014 0.029 0.018 0.037 0.0222013 0.000 0.000 0.017 0.010 0.024 0.0152014 0.011 0.007 0.018 0.011 0.024 0.0152015 0.000 0.000 0.014 0.009 0.030 0.0182016 0.000 0.000 0.000 0.000 0.009 0.0052017 0.000 0.000 0.000 0.000 0.012 0.0072018 0.000 0.000 0.009 0.006 0.017 0.0102019 0.000 0.000 0.007 0.004 0.014 0.009
RTI International Update for Detection of Organic Sulfur in IMPROVE Extracts
Collaborating with Dr. Jason Surratt (UNC Chapel Hill) and Yuzhi Chen (Doctoral Candidate)
Using HILIC Method to Separate Species and Mass Spectrometry to identify species observed in extracts.
Our goal is to identify if OS is in our extracts Identify a method for quantification.
RTI International Update for Detection of Organic Sulfur in IMPROVE Extracts
Name [M-H]- m/z Precursormethanesulfonic acid CH3O3S- 94.98
Dimethylsulfide (DMS)
methyl sulfate CH3O4S- 110.976
Hydroxyacetone sulfate
C3H5O5S-
152.986
Hydroxyacetone/ Methacrolein (MACR)/Methyl vinyl ketone (MVK)
C2H3O6S- 154.97Glycolic acid/ MVK
C3H7O5S- 155.0022 unknown
C3H5O6S-168.981
Isoprene/Green Leaf Volatile (GLV)
C4H7O6S- 182.997Isoprene/MACR/MVK
C5H9O6S- 197.013 Isoprenemethylglyceric acid sulfate C4H7O7S- 198.992 Isoprene
C5H11O6S- 199.028 MBO/ IsopreneC5H7O7S- 210.992 isopreneC5H9O7S- 213.007 isoprene
RTI International Update for Detection of Organic Sulfur in IMPROVE Extracts
methyltetrol sulfate C5H11O7S- 215.023 isoprene
C6H9O7S- 225.007 GLV/IsopreneC8H13O6S- 237.044 MVK
C7H11O7S- 239.023 MACR/MVKC9H13O6S- 249.044 LimoneneC8H11O7S- 251.023 α-pinene
C8H13O7S- 253.039 TerpinolèneC5H10NO9S- 260.008 isoprene
C12H24O4S- 265.148Diesel and biodiesel fuel
C10H15O7S- 279.054
α-/β-pinene; terpinenes/Limonene
C10H17O7S- 281.07
α-terpinene/Limonene
C10H16NO7S- 294.065 α-/β-pinene
C10H15N2O9S- 342.05α-/β-pinene / α-terpinene
RTI International Update for Detection of Organic Sulfur in IMPROVE Extracts
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
ng S
Winter
methyltetrol sulfates methyl sulfates lactic acid sulfate
RTI International Update for Detection of Organic Sulfur in IMPROVE Extracts
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
ng S
Summer
methyltetrol sulfates methyl sulfates lactic acid sulfate
RTI International Next Steps
Verify with secondary analyses.
Calculate amount present in composited samples
Utilize this data as pilot to write up a proposal to request funding.
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